with Pantene. You're about to see a video yourself. Her wife reporting her husband who seems drunk. Police arresting him for a DUI. They thought he was drunk, too. But the medical mystery was he hardly had a drink. It was something else. Here's Deborah Roberts. Reporter: 34-year-old nick Hess is the classic active guy. He bikes, swims, plays volleyball. His wife Karen can barely keep up. I'm the more serious person. He really keeps things lighthearted. We're almost, like, complete opposites. She's the-- the order to the chaos over here I guess. I'm an upbeat, like, a hyperactive, fun guy. Reporter: Even with different personalities and career paths, she's works in an office, he's now a waiter, life was good. But then there was something else, something really strange. We would be watching television, and-- we would watch, you know-- a show-- episode after episode. And by the end of the evening, he would start to be confused, he would start slurring. And he did smell like he had alcohol on his breath. Reporter: Karen began recording nick on her phone. I don't feel good. You don't feel good? Uh. What do you feel like? I feel like I'm on some hard drug or something. Had he been drinking at that point? No. We were-- we were together all day-- watching television. Have you had anything to drink? Nothing, not one thing. Why are you recording me? Cause I want to show this to the doctors. How intoxicated did he appear at times? Oh, it got really-- it got really bad. She was filming me. I was swerving. I used a lot of profanity. When I looked at it, the film that she showed of me, 'cause I wouldn't believe it. My heart just fell, like, straight down. Reporter: Desperate for answers, nick and Karen took their video to doctor after doctor. Even Karen began to wonder if the man she's known for 10 years had a deep secret. I went through the entire house looking-- looking for alcohol. In the mattresses. Everywhere. I mean, everywhere. In between-- the towels in the towel rack. Reporter: There was no evidence that nick may have been drinking until, one night in 2011. When driving just a few blocks from home, nick says, he was hit by an oncoming car. I cut through this alley, and right up here is where the accident happened. I was sitting right here. I picked up my phone and called the police instantly. Reporter: But when they arrive, police quickly make nick the focus of the investigation. Nick, how much had you had to drink tonight? Uh I had one beer. One beer? Yeah. How long ago was that? Um bout 12 hours ago. One beer 12 hours ago? Reporter: Slurring and wobbly, police are convinced he's had more than one beer and insist on a breathalyzer. Blow, blow, blow, there you go. Then startling results. .236 according to the police report. Nick was nearly three times over the legal limit. You are now under arrest for operating a vehicle under the Indiana influence. What did you think when you you got the news that he'd been pulled over for DUI? It just made me more determined to try and figure out what was going on with him. Reporter: Now skittish about driving, nick began biking, but even that would become problematic. Nick took a bad fall and was rushed to the er where he got this news. They couldn't give me medication because they said I had alcohol in my system. When they told me I was drinking I told them they were crazy, I been with my wife all day I had nothing to drink. What's happening with nick? It's a bonafide medical mystery. Karen, certain that her husband is no alcoholic, turns to her computer. For hours, researching. I finally begged her, "Please stop. Like, there's nothing' that we can do anymore. I may just have to live with this. Please stop." Reporter: But luckily for nick, his wife wouldn't stop. I had come across this article about auto brewery. It was, like, "Oh my gosh. This is what he has. I'm convinced of it." Reporter: An aha moment. Auto brewery, Karen learns, is when excess yeast in the intestine ferments carbohydrates and other sugary food into, get this, alcohol. We believe this is where the yeast resides it. Reporter: Dr. Barbara Cordell, one of the authors of the case study, had a patient like nick, who was plagued by inexplicable drunkeness. She put her patient under observation with no access to alcohol. They fed him a high-carbohydrate diet and checked his blood alcohol level every two hours. Reporter: The next day, his blood alcohol level went up on its own. And when they looked at the yeast in his intestines-- This type of yeast that was in our patient is the same yeast that is used to brew beer. Reporter: His stomach was a micro brewery! Now Karen needed to find a local Ohio doctor who would be open to the suggestion. She discovered Harvard trained Dr. Anup kanodia, as for nick's results off the charts! Four times the Normal amount. It picked up the highest level of yeast I've ever seen on a patient. This is what your other doctors are missing. Reporter: So he had nick completely change his diet. We had him take out-- so we had him take out all the foods that break down to sugar. Reporter: Things like breads pasta and rice. And guess what? After just four weeks of making simple diet changes, his strange affliction vanished. No wooziness? No intoxication? No. What did that feel like for you? It was awesome. It's incredible. After dealing with it for so long I was in such major denial. But you had your guy back? Yeah. It was the nick I fell in love with. I'm the luckiest person

This transcript has been automatically generated and may not be 100% accurate.

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{"id":25005343,"title":"These Men Can Get Drunk Without Drinking","duration":"6:02","description":"Auto-Brewery syndrome turned Nick Hess' stomach into a brewery, which converted excess yeast to alcohol.","url":"/2020/video/2020-men-drunk-drinking-25005343","section":"2020","mediaType":"Default"}